Add README to xpumanager sidecar and reference to main README

Signed-off-by: Tuomas Katila <tuomas.katila@intel.com>

Author: tkatila

README.md

@@ -23,6 +23,7 @@ Table of Contents
     * [DLB device plugin](#dlb-device-plugin)
     * [IAA device plugin](#iaa-device-plugin)
 * [Device Plugins Operator](#device-plugins-operator)
+* [XeLink XPU-Manager sidecar](#xelink-xpu-manager-sidecar)
 * [Demos](#demos)
 * [Workload Authors](#workload-authors)
 * [Developers](#developers)
@@ -203,6 +204,12 @@ The [Device plugins operator README](cmd/operator/README.md) gives the installat
 
 The [Device plugins Operator for OCP](cmd/operator/ocp_quickstart_guide/README.md) gives the installation and usage details for the operator available on [Red Hat OpenShift Container Platform](https://catalog.redhat.com/software/operators/detail/61e9f2d7b9cdd99018fc5736).
 
+## XeLink XPU-Manager Sidecar
+
+To support interconnected GPUs in Kubernetes, XeLink sidecar is needed.
+
+The [XeLink XPU-Manager sidecar README](cmd/xpumanager_sidecar/README.md) gives information how the sidecar functions and how to use it.
+
 ## Demos
 
 The [demo subdirectory](demo/readme.md) contains a number of demonstrations for

cmd/xpumanager_sidecar/README.md

@@ -0,0 +1,72 @@
+# XeLink sidecar for Intel XPU Manager
+
+Table of Contents
+
+* [Introduction](#introduction)
+* [Modes and Configuration Options](#modes-and-configuration-options)
+* [Installation](#installation)
+  * [Install XPU-Manager with the Sidecar](#install-xpu-manager-with-the-sidecar)
+  * [Install Sidecar to an Existing XPU-Manager](#install-sidecar-to-an-existing-xpu-manager)
+* [Verify Sidecar Functionality](#verify-sidecar-functionality)
+
+## Introduction
+
+Intel GPUs can be interconnected via an XeLink. In some workloads it is beneficial to use GPUs that are XeLinked together for optimal performance. XeLink information is provided by [Intel XPU Manager](https://www.github.com/intel/xpumanager) via its metrics API. Xelink sidecar retrieves the information from XPU Manager and stores it on the node under ```/etc/kubernetes/node-feature-discovery/features.d/``` as a feature label file. [NFD](https://github.com/kubernetes-sigs/node-feature-discovery) reads this file and converts it to Kubernetes node labels. These labels are then used by [GAS](https://github.com/intel/platform-aware-scheduling/tree/master/gpu-aware-scheduling) to make [scheduling decisions](https://github.com/intel/platform-aware-scheduling/blob/master/gpu-aware-scheduling/docs/usage.md#multi-gpu-allocation-with-xe-link-connections) for Pods.
+
+## Modes and Configuration Options
+
+| Flag | Argument | Default | Meaning |
+|:---- |:-------- |:------- |:------- |
+| -lane-count | int | 4 | Minimum lane count for an XeLink interconnect to be accepted |
+| -interval | int | 10 | Interval for XeLink topology fetching and label writing (seconds, >= 1) |
+| -startup-delay | int | 10 | Startup delay before the first topology fetching (seconds, >= 0) |
+| -label-namespace | string | gpu.intel.com | Namespace or prefix for the labels. i.e. **gpu.intel.com**/xe-links |
+
+The sidecar also accepts a number of other arguments. Please use the -h option to see the complete list of options.
+
+## Installation
+
+The following sections detail how to obtain, deploy and test the XPU-Manager XeLink sidecar.
+
+### Pre-built Images
+
+[Pre-built images](https://hub.docker.com/r/intel/intel-xpumanager-sidecar)
+of this component are available on the Docker hub. These images are automatically built and uploaded
+to the hub from the latest main branch of this repository.
+
+Release tagged images of the components are also available on the Docker hub, tagged with their
+release version numbers in the format `x.y.z`, corresponding to the branches and releases in this
+repository.
+
+Note: Replace `<RELEASE_VERSION>` with the desired [release tag](https://github.com/intel/intel-device-plugins-for-kubernetes/tags) or `main` to get `devel` images.
+
+See [the development guide](../../DEVEL.md) for details if you want to deploy a customized version of the plugin.
+
+#### Install XPU-Manager with the Sidecar
+
+Install XPU-Manager daemonset with the XeLink sidecar
+
+```bash
+$ kubectl apply -k 'https://github.com/intel/intel-device-plugins-for-kubernetes/deployments/xpumanager_sidecar?ref=<RELEASE_VERSION>'
+```
+
+Please see XPU-Manager Kubernetes files for additional info on [installation](https://github.com/intel/xpumanager/tree/master/deployment/kubernetes).
+
+#### Install Sidecar to an Existing XPU-Manager
+
+Use patch to add sidecar into the XPU-Manager daemonset.
+
+```bash
+$ kubectl patch daemonsets.apps intel-xpumanager --patch-file 'https://github.com/intel/intel-device-plugins-for-kubernetes/deployments/xpumanager_sidecar/kustom/kustom_xpumanager.yaml?ref=<RELEASE_VERSION>'
+```
+
+NOTE: The sidecar patch will remove other resources from the XPU-Manager container. If your XPU-Manager daemonset is using, for example, the smarter device manager resources, those will be removed.
+
+#### Verify Sidecar Functionality
+
+You can verify the sidecar's functionality by checking node's xe-links labels:
+
+```bash
+$ kubectl get nodes -A -o=jsonpath="{range .items[*]}{.metadata.name},{.metadata.labels.gpu\.intel\.com\/xe-links}{'\n'}{end}"
+master,0.0-1.0_0.1-1.1
+```